Switch to keybase go-crypto (for some elliptic curve key) + test (#1925)

* Switch to keybase go-crypto (for some elliptic curve key) + test

* Use assert.NoError 

and add a little more context to failing test description

* Use assert.(No)Error everywhere 🌈

and assert.Error in place of .Nil/.NotNil

vendor/github.com/keybase/go-crypto/openpgp/canonical_text.go

@@ -0,0 +1,59 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package openpgp
+
+import "hash"
+
+// NewCanonicalTextHash reformats text written to it into the canonical
+// form and then applies the hash h.  See RFC 4880, section 5.2.1.
+func NewCanonicalTextHash(h hash.Hash) hash.Hash {
+	return &canonicalTextHash{h, 0}
+}
+
+type canonicalTextHash struct {
+	h hash.Hash
+	s int
+}
+
+var newline = []byte{'\r', '\n'}
+
+func (cth *canonicalTextHash) Write(buf []byte) (int, error) {
+	start := 0
+
+	for i, c := range buf {
+		switch cth.s {
+		case 0:
+			if c == '\r' {
+				cth.s = 1
+			} else if c == '\n' {
+				cth.h.Write(buf[start:i])
+				cth.h.Write(newline)
+				start = i + 1
+			}
+		case 1:
+			cth.s = 0
+		}
+	}
+
+	cth.h.Write(buf[start:])
+	return len(buf), nil
+}
+
+func (cth *canonicalTextHash) Sum(in []byte) []byte {
+	return cth.h.Sum(in)
+}
+
+func (cth *canonicalTextHash) Reset() {
+	cth.h.Reset()
+	cth.s = 0
+}
+
+func (cth *canonicalTextHash) Size() int {
+	return cth.h.Size()
+}
+
+func (cth *canonicalTextHash) BlockSize() int {
+	return cth.h.BlockSize()
+}